import time
import tkinter
import threading


root = tkinter.Tk()
root.title('倒计时自动关闭窗口')
root['width'] = 400
root['height'] = 300

root.resizable(False, False)


richText = tkinter.Text(root,width=380)
richText.place(x=10,y=10,width=380,height=230)
richText.insert('0.0','假设阅读这些文字需要10秒时间')

IbTime = tkinter.Label(root,fg='red',anchor='w')
IbTime.place(x=10,y=250,width=150)

def autoClose():
  for i in range(10):
    IbTime['text'] ='距离窗口关闭还有{}秒'.format(10-i)

    time.sleep(1)
  root.destroy()

t = threading.Thread(target=autoClose)
t.start()

root.mainloop()